Are Aldehydes in Heat-Sterllized Peritoneal Dialysis Fluids Toxic in Vitro?

Objective Chemical analysis of several brands of peritoneal dialysis fluids (PD fluids) has revealed the presence of 2-furaldehyde, 5-HMF (5-hydroxymethylfuraldehyde), acetaldehyde, formaldehyde, glyoxal, and methylglyoxal. The aim of this study was to investigate if the in vitro side effects caused by glucose degradation products, mainly formed during heat sterilization, are due to any of these recently identified aldehydes. Design Cell growth media or sterile filtered PD fluids were spiked with different concentrations ofthealdehydes. Measurements In vitro side effects were determined as the inhibition of cell growth of cultured mouse fibro blasts or stimulated superoxide radical release from human peritoneal cells. Results Our results demonstrate that the occurrences of 2-furaldehyde, 5-HMF, acetaldehyde, formaldehyde, glyoxal, or methylglyoxal in heat-sterilized PD fluids are probably not the direct cause of in vitro side effects. In order to induce the same magnitude of cell growth inhibition as the heat-sterilized PD fluids, the concentrations of 2-furaldehyde, glyoxal, and 5-HMF had to be 50 to 350 times higher than those quantified in the PD fluids. The concentrations of acetaldehyde, formaldehyde, and methylglyoxal observed in the heat-sterilized PD fluids were closer to the cytotoxic concentrations although still 3 to 7 times lower. Conclusion Since none of these aldehydes caused in vitro toxicity at the tested concentrations, the toxicity found in PD fluids is likely to be due to another glucose degradation product, not yet identified. However, it is possible that these aldehydes may still have adverse effects for patients on peritoneal dialysis.

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Glucose Degradation Products and Peritoneal Membrane Function

Peritoneal Dialysis International ◽

10.1177/089686080102100218 ◽

2001 ◽

Vol 21 (2) ◽

pp. 201-207 ◽

Cited By ~ 15

Author(s):

Janusz Witowski ◽

Thorsten O. Bender ◽

Gerhard M. Gahl ◽

Ulrich Frei ◽

Achim Jörres

Keyword(s):

Peritoneal Dialysis ◽

Cell Viability ◽

Degradation Products ◽

Membrane Function ◽

Peritoneal Mesothelial Cells ◽

Glucose Degradation Products ◽

And Function ◽

The Impact ◽

Dialysis Fluids

Background The bioincompatibility of peritoneal dialysis fluids (PDF) in current use has been partially attributed to the presence of glucose degradation products (GDPs), which are generated during heat sterilization of PDF. Several of the GDPs have been identified and we have recently demonstrated that these GDPs per se may impair the viability and function of human peritoneal mesothelial cells (HPMC) in vitro. It is also possible that GDP-related toxicity is further exacerbated by the milieu of PDF. We review the current literature on GDP and present the results of experiments comparing the impact of heat- and filter-sterilized PDF on the viability and function of HPMC. Methods Peritoneal dialysis fluids with low (1.5%) and high (4.25%) glucose concentrations were laboratory prepared according to the standard formula and sterilized either by heat (H-PDF; 121°C, 0.2 MPa, 20 minutes) or filtration (F-PDF; 0.2 μ). The buildup of GDP was confirmed by UV absorbance at 284 nm. Confluent HPMC monolayers were exposed to these solutions mixed 1:1 with standard M199 culture medium. After 24 hours, cell viability was assessed with the MTT assay, and interleukin-1β–stimulated monocyte chemotactic protein-1 (MCP-1) release with specific immunoassay. Results Exposure of HPMC to H-PDF resulted in a significant decrease in cell viability, with solutions containing 4.25% glucose being more toxic than 1.5% glucose-based PDF (27.4% ± 3.4% and 53.4% ± 11.0% of control values, respectively). In contrast, viability of HPMC exposed to F-PDF was not different from that of control cells. Moreover, treatment with H-PDF impaired the release of MCP-1 from HPMC to a significantly greater degree compared to F-PDF (17.4% and 24.9% difference for low and high glucose PDF, respectively). Conclusions Exposure of HPMC to H-PDF significantly impairs cell viability and the capacity for generating MCP-1 compared to F-PDF. This effect is likely to be mediated by GDPs present in H-PDF but not in F-PDF.

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3,4-DGE in Peritoneal Dialysis Fluids Cannot be Found in Plasma after Infusion into the Peritoneal Cavity

Peritoneal Dialysis International ◽

10.1177/089686080802800315 ◽

2008 ◽

Vol 28 (3) ◽

pp. 277-282 ◽

Cited By ~ 6

Author(s):

Martin Erixon ◽

Anders Wieslander ◽

Torbjörn Lindén ◽

Ola Carlsson ◽

Jan Åke Jönsson ◽

...

Keyword(s):

Peritoneal Dialysis ◽

Human Plasma ◽

Peritoneal Cavity ◽

Degradation Products ◽

High Reactivity ◽

The Other ◽

Glucose Degradation Products ◽

Pass Through ◽

Dialysis Fluids

Objective Glucose degradation products (GDPs) are important in the outcome of peritoneal dialysis (PD) treatment. 3,4-dideoxyglucosone-3-ene (3,4-DGE) is the most cytotoxic GDP found in conventionally manufactured fluids and may, in addition, be recruited from 3-deoxyglucosone (3-DG). It is not known what happens with those GDPs in patients during PD. The aim of this study was to investigate if the 3,4-DGE and 3-DG in PD fluids can be found in plasma during treatment. Design PD patients were dialyzed with a conventional PD fluid containing 43 μmol/L 3,4-DGE and 281 μmol/L 3-DG. Parallel experiments were performed in rats as well as in vitro with human plasma. The rats were dialyzed with a PD fluid containing 100 μmol/L 3,4-DGE and 200 μmol/L 3-DG. Results The concentration of 3,4-DGE in the peritoneum decreased at a much higher rate than 3-DG during the dwell. 3,4-DGE was not, however, detected in the plasma of patients or rats during dialysis. The concentration of 3-DG in plasma peaked shortly after infusion of the fluid to the peritoneal cavity. The concentration of 3,4-DGE during experimental incubation in plasma decreased rapidly, while the concentration of 3-DG decreased only 10% as rapidly or less. Conclusion 3,4-DGE could not be detected in plasma from either PD patients or rats during dialysis. This is presumably due to its high reactivity. 3-DG may, on the other hand, pass through the membrane and be detected in the blood.

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Glucose Degradation Products in Peritoneal Dialysis Fluids: How they can be Avoided

Peritoneal Dialysis International ◽

10.1177/089686080102103s21 ◽

2001 ◽

Vol 21 (3_suppl) ◽

pp. 119-124 ◽

Cited By ~ 13

Author(s):

Anders Wieslander ◽

Torbjörn Linden ◽

Per Kjellstrand

Keyword(s):

Peritoneal Dialysis ◽

Degradation Products ◽

Low Ph ◽

Relative Importance ◽

In Vitro Methods ◽

Glucose Degradation Products ◽

Peritoneal Tissue ◽

In Vitro Inhibition ◽

Dialysis Fluids

♦ Objectives A patient on peritoneal dialysis (PD) uses 3 – 7 tons of PD fluid every year. The result is considerable stress on the peritoneal tissue. Aspects of PD fluids that have been considered responsible for bioincompatibility are low pH, high osmolality, high glucose and lactate concentrations, and the presence of glucose degradation products (GDPs). However, the relative importance of each factor in PD fluid has so far not been investigated. Discovering their relative importance was the aim of the present study. ♦ Methods Two main methods for investigating biocompatibility were used in this study: cytotoxicity measured as in vitro inhibition of cell growth, and in vitro AGE formation measured as albumin-linked fluorescence. ♦ Results The two most important factors for determining in vitro bioincompatibility of PD fluids were the presence of GDPs, which caused both severe cytotoxicity and strong AGE promotion, and low pH, which induced severe cytotoxicity. ♦ Conclusions The biocompatibility of PD fluids can be monitored through fairly simple in vitro methods such as cell proliferation and AGE formation. Bioincompatibility of PD fluids is caused mainly by the presence of GDPs and low pH. These findings correlate well with known clinical bioincompatibility.

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Degradation in Peritoneal Dialysis Fluids May be Avoided by Using Low pH and High Glucose Concentration

Peritoneal Dialysis International ◽

10.1177/089686080102100402 ◽

2001 ◽

Vol 21 (4) ◽

pp. 338-344 ◽

Cited By ~ 13

Author(s):

Per Kjellstrand ◽

Evi Martinson ◽

Anders Wieslander ◽

Karin Kjellstrand ◽

Elin Jeppsson ◽

...

Keyword(s):

Peritoneal Dialysis ◽

Glucose Concentration ◽

Degradation Products ◽

Heating Time ◽

Uv Absorbance ◽

High Concentration ◽

Number Of Factors ◽

Initial Ph ◽

Dialysis Fluids

Objective When glucose is present in a medical fluid, the heat applied during sterilization leads to degradation. The glucose degradation products (GDPs) give rise to bioincompatible reactions in peritoneal dialysis patients. The extent of the degradation depends on a number of factors, such as heating time, temperature, pH, glucose concentration, and catalyzing substances. In the present work, we investigated the influence of pH and concentration in order to determine how to decrease the amounts of GDPs produced. Design Glucose solutions (1% - 60% glucose; pH 1 - 8) were heat sterilized at 121°C. Ultraviolet (UV) absorption, aldehydes, pH, and inhibition of cell growth (ICG) were used as measures of degradation. Results Glucose degradation was minimum at an initial pH (prior to sterilization) of around 3.5 and at a high concentration of glucose. There was considerable development of acid degradation products during the sterilization process when the initial pH was high. Two different patterns of development of UV-absorbing degradation products were seen: one below pH 3.5, dominated by the formation of 5-hydroxy-methyl-2-furaldehyde (5-HMF); and one above, dominated by degradation products absorbing at 228 nm. 3-Deoxyglucosone (3-DG) concentration and the portion of 228 nm UV absorbance not caused by 5-HMF were found to relate to the in vitro bioincompatibility measured as ICG; there was no relation between 5-HMF or absorbance at 284 nm and bioincompatibility. Conclusion In order to minimize the development of bioincompatible GDPs in peritoneal dialysis fluids during heat sterilization, pH should be kept around 3.2 and the concentration of glucose should be high. 5-HMF and 284 nm UV absorbance are not reliable as quality measures. 3-DG and the portion of UV absorbance at 228 nm caused by degradation products other than 5-HMF seem to be reliable indicators of bioincompatibility.

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3,4-Dideoxyglucosone-3-Ene in Peritoneal Dialysis Fluids Infused into the Peritoneal Cavity Cannot be Found in Plasma

Peritoneal Dialysis International ◽

10.1177/089686080902902s04 ◽

2009 ◽

Vol 29 (2_suppl) ◽

pp. 28-31 ◽

Cited By ~ 6

Author(s):

Martin Erixon ◽

Anders Wieslander ◽

Torbjörn Lindén ◽

Ola Carlsson ◽

Jan Åke Jönsson ◽

...

Keyword(s):

Peritoneal Dialysis ◽

Human Plasma ◽

Peritoneal Cavity ◽

Degradation Products ◽

High Reactivity ◽

The Other ◽

Glucose Degradation Products ◽

Pass Through ◽

Dialysis Fluids

Objective Glucose degradation products (GDPs) are important for the outcome of peritoneal dialysis (PD) treatment. The most cytotoxic GDP found in conventionally manufactured fluids, 3,4-dideoxyglucosone-3-ene (3,4-DGE), may in addition be recruited from 3-deoxyglucosone (3-DG). What happens with the GDPs in the fluid infused into patients during PD is not known. We investigated whether 3,4-DGE and 3-DG in PD fluid can be found in plasma during treatment. Design Patients on PD were dialyzed with a conventional PD fluid containing 43 μmol/L 3,4-DGE and 281 μmol/L 3-DG. Parallel experiments were performed in rats and in vitro with human plasma. The rats were dialyzed with a PD fluid containing 100 μmol/L 3,4-DGE and 200 μmol/L 3-DG. Results The 3,4-DGE concentration in the peritoneum declined at a much higher rate during the dwell than did the 3-DG concentration. However, 3,4-DGE was not detected in the plasma of patients or of rats during dialysis. The 3-DG concentration in plasma peaked shortly after infusion of fluid into the peritoneal cavity. The 3,4-DGE concentration during experimental incubation in plasma declined rapidly; the 3-DG concentration declined only 10% as rapidly (or less). Conclusion During dialysis, 3,4-DGE could not be detected in plasma of either PD patients or rats, presumably because of its high reactivity. On the other hand, 3-DG may pass through the membrane and be detected in the blood.

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δ-Tocopherol Enhances Docetaxel-Induced Growth Inhibition and Apoptosis in Ovarian Cancer SKOV3 Cells

Natural Product Communications ◽

10.1177/1934578x211002298 ◽

2021 ◽

Vol 16 (3) ◽

pp. 1934578X2110022

Author(s):

Hongjuan Chai ◽

Jugang Wu ◽

Junlei Liu ◽

Ting Liu ◽

Qing Ren ◽

...

Keyword(s):

Ovarian Cancer ◽

Side Effects ◽

Cell Growth ◽

Growth Inhibition ◽

Cell Apoptosis ◽

Induction Effect ◽

Apoptosis Induction ◽

Cell Growth Inhibition ◽

Skov3 Cells

Docetaxel is the first-line chemotherapeutic drug for ovarian cancer. However, its clinical use is limited owing to its serious side effects. Therefore, it is of great clinical significance to enhance the efficacy of docetaxel at lower doses in a less-toxic manner. In this study, we investigated whether δ-tocopherol could enhance the anti-tumor effects of docetaxel on ovarian cancer SKOV3 cells in vitro. For docetaxel and δ-tocopherol, IC50 values of 1.89 nM and 11.41 µM, respectively, were obtained, in SKOV3 cells. The combination of δ-tocopherol and docetaxel had a synergistic cell growth inhibition effect, with lower cell viability and more cell arrest at the S phase compared to either δ-tocopherol or docetaxel alone. In addition, the combination of δ-tocopherol and docetaxel had a synergistic cell apoptosis induction effect, with more apoptotic cells and reduced anti-apoptotic protein expression compared to either δ-tocopherol or docetaxel alone. Furthermore, we identified 3 hoursub genes (CAT, EP300, CREBBP), which predicted the prognosis of ovarian cancer, which correlated with δ-tocopherol and docetaxel. In conclusion, the combination of δ-tocopherol and docetaxel presented synergistic cell growth inhibition and cell apoptosis induction effects in SKOV3 cells at a low dose, which suggesting that δ-tocopherol could improve the serious side effects of docetaxel.

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The in vitro assessment of the toxicity of volatile, oxidisable, redox-cycling compounds: phenols as an example

Archives of Toxicology ◽

10.1007/s00204-021-03036-w ◽

2021 ◽

Author(s):

Laia Tolosa ◽

Teresa Martínez-Sena ◽

Johannes P. Schimming ◽

Erika Moro ◽

Sylvia E. Escher ◽

...

Keyword(s):

Cultured Cells ◽

Degradation Products ◽

Degradation Kinetics ◽

Redox Cycling ◽

In Vitro Toxicity ◽

Cross Contamination ◽

Physicochemical Changes ◽

In Vitro Assessment ◽

Biological Performance

AbstractPhenols are regarded as highly toxic chemicals. Their effects are difficult to study in in vitro systems because of their ambiguous fate (degradation, auto-oxidation and volatility). In the course of in vitro studies of a series of redox-cycling phenols, we found evidences of cross-contamination in several in vitro high-throughput test systems, in particular by trimethylbenzene-1, 4-diol/trimethylhydroquinone (TMHQ) and 2,6-di-tertbutyl-4-ethylphenol (DTBEP), and investigated in detail the physicochemical basis for such phenomenon and how to prevent it. TMHQ has fast degradation kinetics followed by significant diffusion rates of the resulting quinone to adjacent wells, other degradation products being able to air-diffuse as well. DTBEP showed lower degradation kinetics, but a higher diffusion rate. In both cases the in vitro toxicity was underestimated because of a decrease in concentration, in addition to cross-contamination to neighbouring wells. We identified four degradation products for TMHQ and five for DTBEP indicating that the current effects measured on cells are not only attributable to the parent phenolic compound. To overcome these drawbacks, we investigated in detail the physicochemical changes occurring in the course of the incubation and made use of gas-permeable and non-permeable plastic seals to prevent it. Diffusion was greatly prevented by the use of both plastic seals, as revealed by GC–MS analysis. Gas non-permeable plastic seals, reduced to a minimum compounds diffusion as well oxidation and did not affect the biological performance of cultured cells. Hence, no toxicological cross-contamination was observed in neighbouring wells, thus allowing a more reliable in vitro assessment of phenol-induced toxicity.

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Effect of β-carotene-rich tomato lycopene β-cyclase (tlcy-b) on cell growth inhibition in HT-29 colon adenocarcinoma cells

British Journal Of Nutrition ◽

10.1017/s0007114508169902 ◽

2008 ◽

Vol 102 (2) ◽

pp. 207-214 ◽

Cited By ~ 15

Author(s):

Paola Palozza ◽

Diana Bellovino ◽

Rossella Simone ◽

Alma Boninsegna ◽

Francesco Cellini ◽

...

Keyword(s):

Cell Growth ◽

Growth Inhibition ◽

Colon Adenocarcinoma ◽

Human Colon ◽

Cell Growth Inhibition ◽

Adenocarcinoma Cells ◽

Ht 29 ◽

Colon Adenocarcinoma Cells ◽

Β Carotene

Lycopene β-cyclase (tlcy-b) tomatoes, obtained by modulating carotenogenesis via genetic engineering, contain a large amount of β-carotene, as clearly visible by their intense orange colour. In the present study we have subjected tlcy-b tomatoes to an in vitro simulated digestion and analysed the effects of digestate on cell proliferation. To this aim we used HT-29 human colon adenocarcinoma cells, grown in monolayers, as a model. Digested tomatoes were diluted (20 ml, 50 ml and 100 ml/l) in culture medium and added to the cells for different incubation times (24 h, 48 h and 72 h). Inhibition of cell growth by tomato digestate was dose-dependent and resulted from an arrest of cell cycle progression at the G0/G1 and G2/M phase and by apoptosis induction. A down-regulation of cyclin D1, Bcl-2 and Bcl-xl expression was observed. We also found that heat treatment of samples before digestion enhanced β-carotene release and therefore cell growth inhibition. To induce with purified β-carotene solubilised in tetrahydrofuran the same cell growth inhibition obtained with the tomato digestate, a higher amount of the carotenoid was necessary, suggesting that β-carotene micellarised during digestion is utilised more efficiently by the cells, but also that other tomato molecules, reasonably made available during digestion, may be present and cooperate with β-carotene in promoting cell growth arrest.

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